How are we measuring the coastal currents in Balneário Camboriú?

1. Where is Balneário Camboriú?

Balneário Camboriú, the world's most renowned municipality in the state of Santa Catarina, Brazil, is an interesting sea-side town. Situated on the Atlantic Ocean, it boasts a highly sought-after stretch of the country's southern coast. This places it with a unique geography and culture.

Geographically, the region is characterized by a serene combination of land and sea features. The coast is studded with breathtaking, mile-long sandy beaches. The most prominent among them is Praia Central, surrounded by tall buildings, making it a bustling and modern skyline. Not only is the beach popular among tourists, but it is also a hub of various water sports. The unpolluted blue waters of the Atlantic Ocean are ideal for swimming, surfing, and other sea sports.

Landward, Balneário Camboriú is bordered by the Serra do Mar mountain range. In addition to adding the natural attractiveness of the area, this mountain range has an effect on the climate. The mountains act to insulate the city to some degree from the harsher weather conditions and also contribute to the existence of a micro-climate that generally remains calm and pleasant throughout the year.

The city is historic and culturally rich. It was a fishing town, and the maritime history still finds expression in the culture of the region. Fishing continues to be among the most significant industries of the local economy, although tourism has grown manyfold with time. The people in the area are close-knit, and the local celebrations are replicated with immense fervor. One of the best examples of such a festival is Festa do Marisco of Balneário Camboriú (Seafood Festival), drawing local residents as well as travelers into Balneário Camboriú to enjoy a variety of freshly prepared seafood treats to the beat of live traditional dance and music.

2. What are the coastal currents off Balneário Camboriú?

Coastal currents off Balneário Camboriú are determined by a multi-dimensional blend of a variety of influences. The tidal forces are one of the major ones. The periodic coming and going of the tides in the region lead to tremendous movement of water. Water rushes towards the shore during high tide but flows back towards the sea during low tide. The tidal currents can be as powerful as anything, especially where there is a narrow channel or an estuary mouth. They are also responsible for transporting sediment, nutrients, and marine organisms, and thereby affect the local marine ecosystem.

Wind systems also make a major contribution to the coastal currents. Southeast winds prevail this coast of Brazil. Surface waters offshore might be driven by these winds and, in doing so, create longshore currents. Speed and direction of these longshore currents are also dependent upon wind intensity and type. Stronger the wind, the more powerful the longshore current, and it might transport sand along a beach, sometimes resulting in beach erosion or accretion elsewhere.

Yet another factor which influences the coastal currents is the bathymetry of the region. The topography beneath the water surface, for example the presence of shallow reefs, deep channels, and slope in seabed varying to great depths, will influence and steer the flow of the currents. Shallow reefs, for example, would act as a barrier and divert or bifurcate the current. Water depth will also specify the velocity of the current; with greater depths there would be more robust and steadier currents.

3. How to track the coastal water drift of Balneário Camboriú?

Surface Drift Buoy Method

The traditional method for monitoring the coastal water drift is through the use of surface drift buoys. They are floating markers launched into the sea. Equipped with tracking devices such as GPS or satellite transmitters, they send signals at regular intervals. By monitoring the path of these buoys over time, researchers can calculate the speed and direction of the surface current. Surface drift buoys do have some drawbacks. They are heavily influenced by wind and waves. Strong winds have the potential to cause the buoys to deviate from the actual current path, hence giving false readings. They can only record information about the surface layer of the water column, while the subsurface currents are left unmeasured.

Anchored Ship Method

The anchored ship method involves utilizing a moored ship as a base for the measurement of currents. Scientists release current meters from the ship at multiple depths to track the velocity and direction of the current. It is more accurate vertically, compared to surface drift buoys. It is, however, time - and labor - intensive. The presence of the ship also has a tendency to disrupt the natural continuity of the current, and measurements are limited to a single point. Unfavorable weather conditions such as high waves and strong winds can exclude or render impossible the installation and maintenance of the equipment.

Acoustic Doppler Current Profiler (ADCP) Method

The Acoustic Doppler Current Profiler (ADCP) is a more advanced and effective instrument for coastal current measurement off Balneário Camboriú. ADCPs are able to make precise measurements of current velocity at several depths within the water column.

4. What is the working principle of ADCPs based on the Doppler principle?

ADCPs operate on the principle of the Doppler principle. They emit sound waves into the water. When these sound waves strike particles in the water, such as suspended sediment or small sea animals, some of the sound energy becomes scattered in the direction of the ADCP. If particles are moving in the direction of the current, the frequency of the scattered sound wave will differ from the original frequency of the sent-out sound wave. This difference in frequency, or Doppler shift, changes in proportion to the particles' velocity and, thus, the current velocity.

Most ADCPs utilize multiple beams, typically four, to measure the Doppler shift in various directions. From analyzing Doppler shifts in the multiple beams, the ADCP current profiler is able to compute the three - dimensional velocity of the current at various depths. The extent to which the current is measured is a function of the frequency of the sound waves used by the ADCP. More frequent ADCPs are better suited for measurements in shallow water because they provide higher resolution but less range. Lower-frequency ADCPs have more penetration into the water column but lower resolution.

5. What are the requirements for high-quality measurement of Balneário Camboriú coastal currents?

A number of attributes are needed in the measurement equipment for high-quality measurement of Balneário Camboriú's coastal currents. Above all, material reliability is a prerequisite. It must be capable of withstanding the harsh sea environment, including sea-water exposure, sea currents, and unpredictable weather. Corrosion - resistant materials are crucial to ensure the long - term functioning of the device. In the case of ADCPs, the casing material has a significant role to play. Titanium alloy is an excellent choice for ADCP casings for Balneário Camboriú's sea waters. Titanium alloy is highly corrosion - resistant, which is crucial to ensure resistance against the corrosive action of saltwater for extended periods of time. It is also light and sturdy, providing a good balance between strength and ease of deployment.

Size, weight, and power consumption are also essential considerations. Lighter and smaller equipment is easier to deploy, especially in remote or hard - to - reach areas. Low - power - consumption equipment can operate for longer durations without frequent recharging or replacement of the batteries, a consideration of particular importance in long - term observation studies. Economical cost - effectiveness is also an issue. In order to provide large - scale measurements and comprehensive - scope data collection, the equipment must be affordable. High - cost equipment will limit the number of measuring points, reducing representativeness and accuracy of data.

6. How to Choose Appropriate Equipment for Current Measurement?

According to Usage

The choice of the appropriate equipment to use for measuring the current is application specific. For ship-based measurements, where the ADCP is mounted on a moving ship, a ship-mounted ADCP is employed. This type of ADCP can measure the current continuously as the ship moves across the water, providing a profile of the current along the ship track.

For long - term, fixed - point observations, a bottom - mounted (or sit - on - the - bottom) ADCP is appropriate. They are placed on the sea floor and can measure current over a long period of time at a fixed location.

If the aim is to monitor the current in a more mobile and wider capacity, a buoy-mounted ADCP can be used. These are installed on floating buoys and can be permitted to drift on the current, making measurements as they move.

Choosing the Right Frequency

The ADCP frequency is another important factor. A 600kHz ADCP can be utilized to quantify currents in water depths of up to 70m. It provides pretty high-resolution measurement in shallow to moderate-depths. A 300kHz ADCP can be used to the depth of up to 110m, whereas a 75kHz ADCP is for way deeper water, up to 1000m. The frequency is chosen as per the projected depth of the water where measurements of currents are going to be done.

There are several well-known ADCP manufacturers on the market, such as Teledyne RDI, Nortek, and Sontek. Nonetheless, for users looking for affordable alternatives, the ADCP supplier China Sonar's PandaADCP is recommended. Constructed entirely of titanium alloy, it has great performance with a reasonable price tag. It is a good option for users who want budget-friendly ADCPs but still need to get coastal current measurements done. For more information, you can visit their official website: https://china-sonar.com/.

Here is a table with some well known ADCP instrument brands and models.